!!

fgSham

Pharmacological and Deep Brain Stimulation Treatments in a Rodent Model of Post-Traumatic Stress Disorder1 2 3 4 5 6 Eric Janezic , Ryan LaHood , David A. Stidd , Jean-Philippe Langevin , Edward French , and Jean-Marc Fellous

1: Program in Neuroscience, University of Arizona, Tucson AZ - 2: Program in Molecular and Cellular Biology, University of Arizona, Tucson AZ - 3: Division of Neurosurgery, University of Arizona, Tucson AZ -4: Department of Neurosurgery, University of California, Los Angeles CA - 5: Department of Pharmacology, University of Arizona, Tucson AZ - 6: Department of Psychology and Program in Applied Mathematics, University of Arizona , Tucson AZ

1. Introduction

2. Methods

3. Results 4. Conclusions

5. References

Refs,etc.

6. Acknowledgements

·

·

·

·

·

·

·

Avoidance of the shock compartment is increased by chronic nicotine suggesting its possible role in memory consolidation. Chronic nicotine increases long term anxiety in the BWBox test but not in the open field test.

Acute administration of OXT immediately after reactivation of the traumatic context may block memory consolidation, and decrease long term anxiety. Chronic OXT post trauma but not during trauma reduces anxiety. Chronic Oxytocin affects touch but not pain sensitivity.

DBS immediately after trauma causes a lasting reduction in anxiety, even after DBS has ceased. The DBS effect can be delayed and still cause reduction in anxiety. DBS affects cue-related anxiety, while paroxetine affects general anxiety.

·

·

·

·

·

·

Post-Traumatic Stress Disorder (PTSD) has a lifetime prevalence of about 7.8% (Kessler et. al., 1995). SSRIs are the most commonly prescribed drug treatments for PTSD with a full remission rate of 20-30% (Berger et. al., 2009). Deregulation of the amygdala (Liberzon and Sripada, 2007) and decreases in baseline dopamine

have been identified as neurophysiological changes in animal models of PTSD. Oxytocin (OXT) has been shown to reduce baseline anxiety in fear-potentiated startle paradigms (Missig e.t al., 2010). Nicotine (NIC) and OXT are known to interact with the dopaminergic system ( Baskerville et. al., 2010 ). Deep Brain Stimulation (DBS) has emerged as a viable treatment for diseases such as depression in humans and has been shown effective in a rodent model of PTSD (Langevin, et. al., 2010).

(Corral-Frias et. al., 2013)

Yin and French, 2000;

—

—

—

—

—

—

Baskerville, T. A., & Douglas, A. J. (2010). Dopamine and oxytocin interactions underlying behaviors: potential contributions to behavioral disorders. CNS neuroscience & therapeutics, 16(3), e92-e123.Berger, William, et al., “Pharmacologic Alternatives to Antidepressants in Post-Traumatic Stress Disorder:

A Systematic Review.” Progress in Neuro-psychopharmacology & Biological Psychiatry 33.2 (2009):169Corral-Frias, Nadia S., et al. “Involvement of the Ventral Tegmental Area in a Rodent Model of Post-

Traumatic Stress Disorder.” Neuropsychopharmacology (2012)Kessler RC, et al., “Post-Traumatic Stress Disorder in the National Comorbidity Survery.” Arch Gen

Psychiatry 52:1048-1060. (1995)Langevin, Jean-Philippe, et al. "Deep brain stimulation of the amygdala alleviates post-traumatic stress

disorder symptoms in a rat model." Journal of psychiatric research 44.16 (2010): 1241-1245.

—Missig et al. Oxytocin reduces background anxiety in fear-potentiated startle paradigm. Neuropsychopharmacology 2010; 35:2607-16—Stidd, D. A., Vogelsang, K., Krahl, S. E., Langevin, J. P., & Fellous, J. M. (2013). Amygdala deep brain stimulation is superior to paroxetine treatment in a rat model of posttraumatic stress disorder. Brain stimulation.—Yin, R., & French, E. D. (2000). A comparison of the effects of nicotine on dopamine and non-dopamine neurons in the rat ventral tegmental area: an in vitro electrophysiological study. Brain research bulletin, 51(6), 507-514.

Liberzon, Israel, and Chandra Sekhar Sripada. "The functional neuroanatomy of PTSD: a critical review." Progress in brain research 167 (2007): 151-169.

Thanks to the Fellous lab for helpful input and discussions. Funding in part by NSF grants 1117388 and 1010172, and the Undergraduate in Biology Research Program at the University of Arizona.

Day -1: Pain (Tail Flick) and tactile (Von Frey) sensitivity tests

Day 8: Pain and tactile sensitivity tests

Day 16: Pain and tactile sensitivity tests

Days -5 to -2: Open field test

Day 15: Open field test

Days 3,5,7: Situational reminders

Day 13: Black and white box test (BWBox)

Day 14: Elevated plus maze

Break

Day 1: Inescapable footshock (2 mA, 10s)

Footshock (2 mA, 1s every 30s for 5 min)

Pharmacological experiments DBS experiments

Tra

um

a

Tra

um

a

Sprague Dawley 3-4 month old male rats.Oxytocin SC injections: 0.2 mg/kg in saline.Oxytocin SC pumps: 7-Day & 14-Day osmotic pumps (4.2 mg/hr).Nicotine SC pumps: 28-Day osmotic pumps (0.02ml/hour).All controls were the Saline (Sal) equivalent.

B. Effect of Oxytocin

-14

-7

-1

1

6

8

15

Acclimation

Recovery

Daily DBS: 120ms pulse at 160 Hz and 2.5 V for 4 hoursParoxetine (PRX): 5 mg/kg IP

Implant electrode into right Basolateral amygdala

Burying assessment

Elevated plus maze

Burying assessment

Burying assessment

Time Spent in Shock Side during Situational

Reminders

Latency to Escape White Side in BWBox Test

Total Distance Covered in Open Field Test

Chronic Nicotine Increases Long Term Anxiety

Chronic Nicotine Does Not Affect Touch and Pain Sensitivity

HippocampusAmygdala

Dopamine

Oxytocin

OtherPVN

VTA

Nicotine pre-pump (n = 9)

Saline pre-pump (n = 7)

Saline (n = 7)

Nicotine (n = 9)

Pe

rce

nta

ge

of

time

sp

en

t in

sh

ock

sid

e (

ou

t o

f 1

20

s)

SR1 SR2 SR30%

5%

10%

15%

20%

25%

30%

*

La

ten

cy t

o E

sca

pe

(s)

0

4

8

12

16

20

Both groups are more anxious after trauma (** = p < 0.01). There is no difference between the two groups.

Nicotine animals are more anxious than controls 13 days after shock (* = p < 0.05).

Nicotine brings the animals to maximal avoidance on SR1. This suggests that nicotine increases sensitivity to context (* = p < 0.05).

Post-Shock

Me

an

Dis

tan

ce (

m)

Pre-Shock

10

12

0

2

4

6

8

Pre-shock Post-shock7 days

Post-shock16 days

Von Frey Touch Sensitivity

Shock

0

10

20

30

40

50

60

Sensi

tivity

Thre

shold

(g)

Sensi

tivity

Thre

shold

(g)

Tail Flick Pain Sensitivity

Nicotine pre-pump (n = 11)

Saline pre-pump (n = 11)

ShockNicotine (n = 11)

Saline (n = 7)

Pre-shock Post-shock7 days

Post-shock16 days

0

1

2

3

4

5

6

7

8

9

Late

ncy

for

with

dra

wal (

s)

Late

ncy

for

with

dra

wal (

s)

7-Day Chronic Oxytocin Administration Increases Anxiety in BWBox Test

Entries into White Side

* = p < 0.05

Time Spent in White Side

* = p < 0.05, ** = p < 0.010

20

40

60

80

100

120

140

160

180

200

Tim

e (

s)

0%

10%

20%

30%

40%

50%

60%

Pre-Shock Post-Shock

Time Spent in Center of Open Field

7 Day OXT (n = 11)

14 Day OXT (n = 11)

SC OXT (n = 9)

Sal Pump (n = 8)

SC Sal (n = 9)

Perc

ent of 500 s

eco

nds

Acute administration of OXT immediately after reactivation of the traumatic context may block memory consolidation, and decrease long term anxiety. Chronic OXT post trauma but not during trauma reduces anxiety .(* = p < 0.05, ** = p < 0.01)

Shock

Left: In control conditions, rats do not bury a novel object. Right: After shock, rats bury the item that was present during trauma (Stidd et. al., 2013).

Time (s)

100

200

300

400

500

Pre-Shock Post-Shock DBS-Sham Sham-DBS

Histology shows that the electrodes were correctly placed in the right basolateral amygdala (Stidd et. al., 2013).

Time-lapse of Ball-Burying Behavior Placement of DBS Electrodes

Oxytocin and Dopamine Pathways

A. Effect of Nicotine

C. Effect of DBS of the Amygdala

Num

ber

of E

ntr

ies

0

1

2

3

4

5

6

7

8

9

543.25/ II5

Sham

Sham

DB

S

DB

S

Chronic Oxytocin Increases Touch Sensitivity, But Not Pain Sensitivity

Pre-Shock 7 Days Post-Shock

7 Days Post-Shock

Von Frey Touch Sensitivity

16 Days Post-Shock

16 Days Post-Shock

0

5

10

15

20

25

30

35

Shock

** = p < 0.01

Tail Flick Pain Sensitivity

0

1

2

3

4

5

6

7

8

9

10

Pre-Shock

Shock

***

**

*

*

*

*

*

*

*

*

*

**

****

7 Day OXT (n = 11)

14 Day OXT (n = 11)

SC OXT (n = 9)

Contact Information: ejanezic@email.arizona.edu

Tim

e (

sec)

DBS does not affect general anxiety as shown by the elevated plus maze, but paroxetine does (* = p < 0.05, adapted from Stidd et. al. 2013).

DBS-Sham (n = 10)

Sham-DBS (n = 10)

PRX (n = 10)

Controls (n = 10)

0

50

100

150

200

250

Controls PRX Sham-DBS DBS-Sham

Tim

e (

sec)

DBS for 1 week after trauma shows less anxiety than all other groups, which persists up to 2 weeks after shock even when DBS has stopped. DBS also reduces anxiety even when started one week after initial trauma (* = p < 0.05). Paroxetine is uneffective (Adapted from Stidd et. al., 2013).

0

20

40

60

80

100

120

140

160

180

200

Baseline pre-shock

1 week post-shock

2 weeks post-shock

Shock

Time in Open Arm of Elevated Plus Maze

Time Spent Burying Object

7 Day OXT (n = 11)

14 Day OXT (n = 11)

SC OXT (n = 9)

7 Day OXT (n = 11)

14 Day OXT (n = 11)

SC OXT (n = 9)

7 Day OXT (n = 11)

14 Day OXT (n = 11)

SC OXT (n = 9)

Paro

xetin

e

*

*

**

**

VTA

HCAMG

PVN

Dopamine

Oxytocin

Unknown